Temporal variation Analysis of New South Wales Streamflow Using Mann-Kendall test

摘要

The Australian continent experiences high interannual climate variability, particularlyin precipitation and rainfall rates.The variability in inflow to dams and catchmentsobserved in logn time over Newsouthw. NSW has experienced a rainfall decrease sincethe mid-1990s, translating into an inflow reduction. The percentage reduction in infl owis far greater, and this factor grows as the drying condition persists. The main objectiveof this study is to examine trends by using Mann Kendall’s tau test in monthlystreamflow data of New South Wales over a 61 years and 33 year period (1951-2011 &1979- 2011). This study reveals that declining trends dominates over uptrend, anddirection of decreasing trend was 66.12% and the increasing trend was found to be33.46 % of the total stations. Significant finding revelas that maximum mean monthlyrainfall in new south wales was recorded in the month of January (61mm) followed bya December (55 mm) and November (48mm) whereas minimum rainfall was recordedin the month of September (35mm) followed by august (36) and April(38mm).Whereas least rainfall in a year of 2002 (310mm) followed by 1982 (320mm). Meanmonthly temperatures was analyzed for period by using the simple mean and increasingtrend was observed in mean temperatures of New South Wales. Mean yearly temp wasanalyzed for the period (1950-2011) by using the simple mean and increasing trend wasobserved in mean temperatures of New South Wales. These results indicate that NewSouth Wales is generally getting drier. Systematic patterns were found in the trends ofmean monthly streamflows of New South Wales. These trends might be a part of theresult of a climate change. Precipitation is a significant but not the only cause ofstreamflow changes in New South Wales. This analysis provides clear understandingand existing relation relationship between rainfall and streamflow because rainfall is achief integrator of runoff streamflow. It will beneficiary for socio-economic activitesand forecasting in New south wales.